The Egg Safety Center said Wright Country Egg of Galt, Iowa expanded a nationwide recall to 380 million eggs from the initial recall of 228 million.

The FDA said the salmonella outbreaks nationwide have increased since May, sparking an investigation of the foodborne illness in 13 states.

The administration said the state and local officials were investigating salmonella cases in Arizona, California, Colorado, Connecticut, Massachusetts, Maryland, Minnesota, North Carolina, Nevada, Oregon, Pennsylvania, Tennessee and Texas.

According to the FDA, the number of salmonella cases reported each week, normally around 50, expanded to 200 within a week since May. Preliminary investigations showed that eggs from Wright County Egg were the potential source.

Los Angeles County officials said on Tuesday that about 266 cases of salmonella in California have been linked to the eggs.

“There have been confirmed Salmonella enteritidis illnesses relating to the shell eggs and traceback investigations are ongoing,” Wright County Egg said in a statement.

The company is part of DeCoster Farms, which is a family-run agribusiness that is a large egg producer. There was no answer to several calls on Wednesday to DeCoster offices in Clarion, Iowa.

The administration said it was conducting an investigation with the Iowa company, including sampling, reviewing records and searching for potential sources of contamination like feed.

Wright County Egg said it was cooperating fully with the FDA’s investigation and was diverting its eggs to a breaker for pasteurization to kill any harmful bacteria.

Salmonella causes fever, diarrhea, vomiting and abdominal pain, and in the most serious cases, death. No deaths have been reported so far.